Circumferential trigger wire for deploying an endoluminal prosthesis

ABSTRACT

A deployment device for deploying an expandable endoluminal prosthesis within a body vessel may include an elongate member extending longitudinally along at least a portion of a length of the deployment device. The deployment device may include at least one engagement member coupled to the elongate member and extending outwardly from the elongate member. The deployment device may include a circumferential trigger wire extending at least partially circumferentially around the elongate member and removably received between the engagement member and the elongate member. The circumferential trigger wire may be manipulatable from a distal end of the deployment device, whereby the circumferential trigger wire is removable from between the engagement member and the elongate member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.15/062,762, filed Mar. 7, 2016, which is a continuation application ofU.S. Ser. No. 13/713,517, filed Dec. 13, 2012, which issued on Mar. 8,2016 as U.S. Pat. No. 9,278,018, which claims priority and the benefitof provisional U.S. Patent Application Ser. No. 61/570,439, filed Dec.14, 2011, which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

This disclosure relates generally to apparatus and methods for treatingmedical conditions. More specifically, this disclosure relates toapparatus and methods for deploying endoluminal prostheses in bodyvessels to treat those medical conditions.

BACKGROUND

Endoluminal prostheses may be inserted into a body lumen such as ananatomical vessel or duct for various purposes. Prostheses may maintainor restore patency in a formerly blocked or constricted passageway, forexample, following a balloon angioplasty procedure. Other prostheses maybe used for different procedures. For example, a prosthesis may includeone or more stents placed in or about a graft, and the stents may holdthe graft in an open configuration to treat an aneurysm. Additionally,stents coupled to one or both ends of a graft may extend proximally ordistally away from the graft to engage a healthy portion of a vesselwall away from a diseased portion of an aneurysm to provide endovasculargraft fixation.

Stents may be either self-expanding or balloon-expandable. In someexamples, stents can have characteristics of both self-expanding andballoon-expandable stents. Self-expanding stents may be delivered to atarget site in a compressed configuration and subsequently expanded byremoving a delivery sheath, removing trigger wires, and/or releasingdiameter reducing ties. A self-expanding stent expands primarily basedon its own expansive force without the need for further mechanicalexpansion. A stent may be made of a shape-memory alloy such as nitinol.The shape-memory alloy may be employed to cause the stent to return to apredetermined configuration upon removal of the sheath or other devicemaintaining the stent in its predeployment configuration.

Deployment devices are used to deploy prostheses, particularly thoseincluding self-expanding stents, within various body lumens. In somedeployment devices, trigger wires are used to restrain a prosthesis in aparticular position on the deployment device or to restrain one or moreself-expanding stents of the prosthesis in a compressed state. Thetrigger wires may releasably couple the proximal and/or distal ends ofthe prosthesis to the deployment device. Typically, one or more triggerwires are looped through a portion of a stent near a vertex of thestent. For example, trigger wires may be used to restrain a “Z-stent” orGianturco stent having a series of substantially straight segmentsinterconnected by a series of bent segments. The trigger wires may bedisposed through, and pull upon, the bent segments to pull the stentclosely against the deployment device.

In the region of the deployment device in which the prosthesis iscarried, trigger wires can foul or catch with stent components on theprosthesis, particularly when the deployment device is bent to passthrough convolutions in the anatomical vessel or duct. This may causeinaccurate deployment or even jamming or breakage of the trigger wire.

Trigger wires also may be used in conjunction with different stentdesigns such as cannula-cut stents having relatively acute or pointedbends. The designs of cannula-cut stents may facilitate compression ofthe stents to a relatively small delivery profile due to the tight bendsof the apices. With such stents, the trigger wires may be looped aroundone or more vertices formed at the proximal and/or distal apices, e.g.,a location where an individual apex splits into two separate strutsegments.

If trigger wires are threaded through the vertices of such cannula-cutstents, the trigger wires may become crimped at the vertices duringcompression of the stents to a reduced diameter delivery profile. If thetrigger wires are crimped between the strut segments, the trigger wiresand/or strut segments may become damaged. Furthermore, when compressingcannula-cut stents having relatively acute bends to a significantlyreduced radial profile, barbs disposed near the apices of the stents maybecome entangled with the stent struts and/or the trigger wires.

Typically, multiple trigger wires are threaded through multiple verticesof a stent to restrain the end of the stent in the reduced diameterdelivery profile. Additional trigger wires may be added to more securelyrestrain the stent. However, such additional trigger wires may increasethe retraction force that is required to release the stent. Suchadditional trigger wires also may increase the likelihood of one or moreof the trigger wires becoming entangled with portions of the stent suchas barbs.

In view of the above, it would be desirable to provide an apparatusconfigured to release a stent with a reduced retraction force while alsoreducing the likelihood of entanglement and damage to the trigger wiresand stent struts.

SUMMARY

The present embodiments provide an endoluminal prosthesis forimplantation within a human or animal body for repair of damagedvessels, ducts, or other physiological pathways and systems and methodfor delivering such an endoluminal prosthesis.

In one example, a deployment device for deploying an expandableendoluminal prosthesis within a body vessel may include an elongatemember extending longitudinally along at least a portion of a length ofthe deployment device. The deployment device may include at least oneengagement member coupled to the elongate member and extending outwardlyfrom the elongate member. The deployment device may include acircumferential trigger wire extending at least partiallycircumferentially around the elongate member and removably receivedbetween the engagement member and the elongate member. Thecircumferential trigger wire may be manipulatable from a distal end ofthe deployment device, whereby the circumferential trigger wire isremovable from between the engagement member and the elongate member.

In another example, a system may include a deployment device and anexpandable endoluminal prosthesis positioned on the deployment device.The deployment device may include a tubular trigger wire guide. Thetubular trigger wire guide may include at least one axial trigger wireaperture in the trigger wire guide and at least one circumferentialtrigger wire aperture in the trigger wire guide. The system may includeat least one axial trigger wire received within the trigger wire guide.The axial trigger wire may extend through the axial trigger wireaperture and exit the trigger wire guide. The system may include acircumferential trigger wire received within the trigger wire guide. Thecircumferential trigger wire may extend through the circumferentialtrigger wire aperture and exit the trigger wire guide and at leastpartially encircle the prosthesis. The circumferential trigger wire maybe engaged by the axial trigger wire and restrain at least a portion ofthe prosthesis in a compressed configuration.

In another example, a method of deploying an endoluminal prosthesis mayinclude providing a deployment device including a tubular trigger wireguide. The trigger wire guide may include at least one axial triggerwire aperture in the trigger wire guide. An axial trigger wire may bereceived within the trigger wire guide and extend through the axialtrigger wire aperture such that a curve of the axial trigger wire isdisposed external of the trigger wire guide. A circumferential triggerwire may at least partially encircle the trigger wire guide. The methodmay include manipulating the circumferential trigger wire from a distalend of the deployment device, and sliding the circumferential triggerwire out of engagement between the curve of the axial trigger wire andan outer surface of the trigger wire guide.

Other systems, methods, features, and advantages of the invention willbe, or will become, apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features, andadvantages be within the scope of the invention, and be encompassed bythe following claims.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 depicts one embodiment of a deployment device for deploying anendoluminal prosthesis.

FIG. 2 depicts the deployment device of FIG. 1 with a sheath retractedto expose an endoluminal prosthesis loaded on the deployment device.

FIG. 3 depicts one embodiment of a trigger wire guide.

FIG. 4 depicts another embodiment of a trigger wire guide.

FIG. 5 is a partial longitudinal cross sectional view of the deploymentdevice of FIG. 1 and a prosthesis restrained by an axial trigger wire.

FIG. 6 depicts one embodiment of a stent.

FIG. 7 depicts the stent of FIG. 6 with a proximal end of the stentpartially restrained by a plurality of conventional axial trigger wires.

FIG. 8 is a partial longitudinal cross sectional view of the engagementbetween a conventional axial trigger wire and the stent as shown in FIG.7.

FIG. 9 depicts an intermediate portion of one embodiment of a deploymentdevice with axial trigger wires loaded therein.

FIG. 10 is a transverse cross sectional view of the deployment devicetaken along line 10-10 of FIG. 9.

FIG. 11 depicts an intermediate portion of the deployment device of FIG.9 with a prosthesis restrained by a circumferential trigger wire.

FIG. 12 is a partial longitudinal cross sectional view of the engagementbetween an axial trigger wire, a circumferential trigger wire, and aprosthesis as shown in FIG. 11.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

The present disclosure relates to apparatus and methods for deployingendoluminal prostheses in body vessels to treat various medicalconditions.

In the present disclosure, the term “proximal” refers to a directionthat is generally closest to the heart during a medical procedure, whilethe term “distal” refers to a direction that is farthest from the heartduring a medical procedure.

FIGS. 1-2 show one embodiment of a deployment device 100 for deployingan endoluminal prosthesis 200. The deployment device 100 may include aguide wire catheter 110. The guide wire catheter 110 may be configuredas an elongate tubular member having a distal end 112, a proximal end114, and a lumen extending longitudinally between the distal andproximal ends of the guide wire catheter. In use, the distal end 112 maybe adapted to remain outside of the body of the patient while theproximal end 114 may be adapted for insertion into a body vessel withinthe body of the patient. To that end, a nose cone dilator 116 may bepositioned at the proximal end 114 of the guide wire catheter 110. Thenose cone dilator 116 may be configured as an elongate tapered extensionto aid in advancing the proximal end of the deployment device 100 withinthe body vessel. The nose cone dilator 116 may include a lumenconfigured to receive a guide wire. The guide wire catheter 110 mayinclude a connector 117 (e.g., a Luer Lock hub) disposed at the distalend 112 of the guide wire catheter. The connector 117 may be configuredto enable the introduction of liquids (e.g., contrast media ortherapeutic agents) during a deployment procedure. In one example, anangiographic contrast fluid may be introduced into the connector 117.The contrast fluid may travel through the guide wire catheter 110 to thenose cone dilator 116 where the contrast fluid may be ejected from oneor more side ports 115 in the nose cone dilator.

A pusher catheter 120 may surround at least a portion of the guide wirecatheter 110. The pusher catheter 120 may be configured as an elongatetubular member having a distal end 122, a proximal end 124, and a lumenextending longitudinally between the distal and proximal ends of thepusher catheter. The guide wire catheter 110 may be movablelongitudinally and/or rotationally with respect to the pusher catheter120. In one example, the guide wire catheter 110 may be moved proximallyor distally within the pusher catheter 120 to move the nose cone dilator116 relative to the pusher catheter. A pin vise 119 may be positionednear the distal end 112 of the guide wire catheter 110 and configured tolock the guide wire catheter in place relative to the pusher catheter120.

A sheath 130 may surround at least a portion of the pusher catheter 120.The sheath 130 may be configured as an elongate tubular member having adistal end 132, a proximal end 134, and a lumen extending longitudinallybetween the distal and proximal ends of the sheath. A sheath hub 136 maybe positioned at the distal end 132 of the sheath 130. The sheath hub136 may include a side tube 138. The side tube 138 may include aconnector (not shown) configured to enable the introduction of liquidsbetween the sheath 130 and the pusher catheter 120.

A recess 118 may be formed between the nose cone dilator 116 and theproximal end 124 of the pusher catheter 120 as shown in FIGS. 1-2. Inother embodiments, a portion of the pusher catheter 120 may beconfigured as a trigger wire guide as further described below. In theseembodiments, the recess 118 may surround a segment of the pushercatheter 120 having a smaller diameter than the remainder of the pushercatheter. The prosthesis 200 may be received in the recess 118 fordelivery to a desired location within a body vessel. The prosthesis 200may be restrained in a compressed delivery configuration within thelumen of the sheath 130. Upon retraction of the sheath 130 to expose theprosthesis 200, the prosthesis may at least partially expand to anexpanded configuration. A portion of the prosthesis 200 may berestrained in the compressed configuration even after retraction of thesheath 130. For example, a proximal end 202 of the prosthesis 200 may berestrained in the compressed configuration by a trigger wire system asfurther described below.

The deployment device 100 may include a trigger wire system configuredto restrain at least a portion of the prosthesis 200 in the compressedconfiguration. The trigger wire system may include one or more axialtrigger wires 142 extending generally longitudinally along at least aportion of the length of the deployment device 100. In one example, thetrigger wire system may include four axial trigger wires as shown inFIGS. 1-4. In another example, the trigger wire system may include sixaxial trigger wires as shown in FIGS. 9-11. In other examples, thetrigger wire system may include any number of axial trigger wires. Theaxial trigger wires 142 may be attached to an axial trigger wire releasemechanism 121, which may be positioned near the distal end 122 of thepusher catheter 120. The axial trigger wires 142 may extend proximallythrough the deployment device 100 in the annular space between thepusher catheter 120 and the guide wire catheter 110. The axial triggerwires 142 may exit the proximal end 124 of the pusher catheter andextend into the recess 118. The axial trigger wires 142 may engage theprosthesis 200 to restrain at least a portion of the prosthesis in thecompressed configuration as further described below. Alternatively, oradditionally, the axial trigger wires 142 may engage a circumferentialtrigger wire 146 also as further described below. The proximal end ofeach axial trigger wire may be releasably received within the nose conedilator 116 and/or the guide wire catheter 110 to maintain tension onthe axial trigger wire to restrain the prosthesis 200. The nose conedilator 116 and/or the guide wire catheter 110 may frictionally engagethe received proximal end of the axial trigger wire 142 to maintaintension on the axial trigger wire. Alternatively, or additionally, theproximal end of the axial trigger wire 142 may be releasably attached tothe nose cone dilator 116 and/or the guide wire catheter 110 by anysuitable means including, for example, an adhesive or a mechanicalattachment mechanism.

The trigger wire system may include at least one circumferential triggerwire 146 (see FIGS. 11-12) extending generally longitudinally along atleast a portion of the length of the deployment device 100. Thecircumferential trigger wire 146 may be attached to a circumferentialtrigger wire release mechanism 123, which may be positioned near thedistal end 122 of the pusher catheter 120. In one example, thecircumferential trigger wire release mechanism 123 may be positionedjust distal of the axial trigger wire release mechanism 121 as shown inFIGS. 1-2. A distal portion of the circumferential trigger wire 146 mayextend proximally through the deployment device 100 in the annular spacebetween the pusher catheter 120 and the guide wire catheter 110. Thecircumferential trigger wire 146 may exit the proximal end 124 of thepusher catheter and extend into the recess 118. A proximal portion ofthe circumferential trigger wire 146 may engage the prosthesis 200 torestrain at least a portion of the prosthesis in the compressedconfiguration as further described below. The proximal end of thecircumferential trigger wire 146 may be releasably received within thenose cone dilator 116 and/or the guide wire catheter 110 to maintaintension on the circumferential trigger wire to restrain the prosthesis200. The nose cone dilator 116 and/or the guide wire catheter 110 mayfrictionally engage the received proximal end of the circumferentialtrigger wire 146 to maintain tension on the circumferential triggerwire. Alternatively, or additionally, the proximal end of thecircumferential trigger wire 146 may be releasably attached to the nosecone dilator 116 and/or the guide wire catheter 110 by any suitablemeans including, for example, an adhesive or a mechanical attachmentmechanism.

The deployment device 100 may include an elongate member such as, forexample, a trigger wire guide 150 as shown in FIG. 3. The trigger wireguide 150 may surround a portion of the guide wire catheter 110 near thenose cone dilator 116. Inside the recess 118, the axial trigger wires142 may enter a distal end of the trigger wire guide 150. The triggerwire guide 150 may have any suitable configuration including, forexample, those described in U.S. Pat. No. 7,803,177 to Hartley et al.,which is incorporated by reference herein in its entirety. In theexample shown in FIG. 3, the trigger wire guide 150 may be configured asa tubular member surrounding at least a portion of the guide wirecatheter 110. The trigger wire guide 150 may include one or more triggerwire lumens 152 extending longitudinally within the trigger wire guide.The trigger wire guide 150 may include one or more elongate apertures154. Each elongate aperture 154 may extend through the outer wall of thetrigger wire guide 150 to the corresponding trigger wire lumen 152. Forexample, the trigger wire guide 150 may include four trigger wire lumens152 as shown in FIG. 3. An axial trigger wire 142 may be received withineach trigger wire lumen 152. Each axial trigger wire 142 may extendproximally within the trigger wire lumen 152 to the correspondingelongate aperture 154.

An engagement member may be coupled to the elongate member and mayextend outwardly from the elongate member. For example, at the elongateaperture 154, the axial trigger wire 142 may exit the trigger wire guide150, extend further proximally, and reenter the trigger wire guidethrough the elongate aperture. In this manner, the portion of the axialtrigger wire 142 external of the trigger wire guide 150 may form anengagement member configured as a curve 144. The curve 144 may becoupled to the trigger wire guide 150 by the engagement of the axialtrigger wire 142 with the elongate aperture 154. The curve 144 may beconfigured to engage the prosthesis 200 and/or the circumferentialtrigger wire 146 as further described below.

Although the engagement member is generally described herein as thecurve 144 formed by the axial trigger wire 142, the disclosure is not solimited. In other examples, an engagement member may be positioned nearthe nose cone dilator 116 to engage the circumferential trigger wire 146as further described below. For example, opposite ends of a wire segmentmay be attached to the trigger wire guide 150, and an intermediateportion of the wire segment may form the engagement member. In thisexample, the wire segment may not be received within the trigger wireguide 150. Additionally, or alternatively, the wire segment may notextend to the distal end of the deployment device as described hereinwith reference to the axial trigger wire 142. In another example, aprotrusion (e.g., a loop or eyelet) may extend from the trigger wireguide 150 to form the engagement member. The protrusion may be formedseparately from or integrally with the trigger wire guide 150. Theprotrusion may include an opening to engage the circumferential triggerwire 146 as further described below. Such alterations are contemplatedby and within the scope of this disclosure.

In any of the examples described herein, the trigger wire guide mayinclude a pair of openings 154 a, 154 b in place of the elongateaperture 154 as described below with reference to FIGS. 9-12. In any ofthe examples described herein, an annular space may be formed betweenthe trigger wire guide 150 and the guide wire catheter 110. The triggerwire lumens 152 may be omitted, and the axial guide wires 142 and/or thecircumferential guide wire 146 may be received within the annular space,also as described below with reference to FIGS. 9-12. Such alternativeembodiments are within the scope of this disclosure.

FIG. 4 shows an alternative example of a trigger wire guide 160. In anyof the examples described herein, the trigger wire guide 160 (or variousfeatures thereof) may be used in place of or in addition to the triggerwire guide 150. In this example, the trigger wire guide 160 may includea tubular guide portion 162 and an enlarged engagement portion 164. Thetrigger wire guide 160 may surround the guide wire catheter 110 asdescribed above with reference to the trigger wire guide 150. A distalend 163 of the tubular guide portion 162 may be positioned near theproximal end 124 of the pusher catheter 120. In one example, the distalend 163 of the tubular guide portion 162 may be received within thelumen of the pusher catheter 120. In another example, the trigger wireguide 160 and the pusher catheter 120 may be formed as a unitary tubularstructure, and the tubular guide portion 162 may extend from theproximal end 124 of the pusher catheter. Positioning the distal end 163of the trigger wire guide 160 near the proximal end 124 of the pushercatheter 120 may reduce the length of the axial trigger wires 142 and/orthe circumferential trigger wire 146 that may be exposed within therecess 118 of the deployment device 100. This may reduce the potentialfor snagging or catching a trigger wire on a portion of the prosthesis200 or the deployment device 100 during deployment of the prosthesis.

The enlarged engagement portion 164 of the trigger wire guide 160 mayextend proximally from a proximal end 165 of the tubular guide portion162. The enlarged engagement portion 164 may extend to the nose conedilator 116. The tubular guide portion 162 may have a diameter that issmaller than the diameter of the enlarged engagement portion 164. Thesmaller diameter tubular guide portion 162 may span a majority of thelength of the recess 118 so that the prosthesis 200 may be compressedaround the tubular guide portion for delivery. The enlarged engagementportion 164 may be configured to engage the proximal end 202 of theprosthesis 200 as further described below.

An annular space 166 may be formed between the guide wire catheter 110and the trigger wire guide 160. The axial trigger wires 142 and thecircumferential trigger wire 146 may extend longitudinally along thedeployment device 100 within the annular space 166. The enlargedengagement portion 164 of the trigger wire guide 160 may include one ormore elongate apertures 154. The elongate apertures 154 may beconfigured generally as described above with reference to the triggerwire guide 150. Each elongate aperture 154 may be in communication withthe annular space 166 between the guide wire catheter 110 and thetrigger wire guide 160. The axial trigger wires 142 may pass through theelongate apertures 154 to form the curves 144 to engage the prosthesis200 and/or the circumferential trigger wire 146. The circumferentialtrigger wire 146 may pass through circumferential trigger wire openingsin the trigger wire guide 160 to engage the prosthesis 200 as furtherdescribed below.

FIG. 5 is a longitudinal cross sectional view of a proximal portion ofthe prosthesis 200 loaded on the deployment device 100. In the viewshown in FIG. 5, the sheath 130 has been retracted to enable partialexpansion of the prosthesis 200. The proximal end 202 of the prosthesis200 may be restrained in the compressed configuration by the triggerwire system. For example, the axial trigger wire 142 may extend throughthe aperture 154 of the trigger wire guide 150 to form the curve 144 asdescribed above. The curve 144 of the axial trigger wire 142 may engagea proximal stent 210 of the prosthesis 200. To that end, the axialtrigger wire 142 may pass through a bend 212 interconnecting twoadjacent struts 214 of the proximal stent 210. The axial trigger wire142 may restrain the engaged bend 212 of the proximal stent 210 in closeproximity to the trigger wire guide 150. Multiple axial trigger wires142 may engage multiple bends 212 of the proximal stent 210 to restraineach engaged bend of the proximal stent in close proximity to thetrigger wire guide 150. In this manner, the proximal end 202 of theprosthesis 210 may be restrained in the compressed configuration.

When the proximal stent 210 is compressed for delivery (e.g., when theprosthesis 200 is compressed within the sheath 130), the axial triggerwire 142 disposed through the bend 212 as shown in FIG. 5 may becomepinched between the struts 214 of the stent. This may damage the stent210 and/or the axial trigger wire 142. Thus, it may be beneficial forthe axial trigger wires to engage the proximal stent of the prosthesisat locations other than the bends between adjacent struts of the stent.

U.S. Patent Application Pub. No. 2009/0204202 by Dierking et al., whichis incorporated by reference herein in its entirety, describes stentdesigns which may be deployed using the deployment device 100 describedherein. For example, FIG. 6 shows an alternative embodiment of aproximal stent 220. The prosthesis 200 may include the proximal stent220 as opposed to the proximal stent 210 described above. Alternatively,the stent 210 may be modified to include one or more of the features ofthe stent 220 (e.g., the end regions 226) described below. The proximalstent 220 may include one or more first proximal apices 221 a. Eachfirst proximal apex 221 a may include an end region 226 having anaperture 227 formed therein. The aperture 227 may be configured toreceive an axial trigger wire 142 as further described below. The endregion 226 may be positioned proximal of the bend 222 between twoadjacent struts 224 of the stent 220 so that, upon compression of theprosthesis 200, the axial trigger wire 142 may not be pinched betweenthe adjacent struts of the proximal stent 220. In other words, the endregion 226 may be configured as an eyelet extending proximally from thebend 222 between two adjacent struts 224 to receive an axial triggerwire 142. The eyelet may remain open even after compression of the stent220.

Additionally, or alternatively, the proximal stent 220 may include oneor more second proximal apices 221 b. Each second proximal apex 221 bmay include an end region 228 having an integral barb 229 formedtherein. The barb 229 may be configured to engage a wall of a bodyvessel upon implantation of the prosthesis 200 to prevent migration ofthe prosthesis within the body vessel. The proximal stent 220 mayinclude alternating first proximal apices and second proximal apices, asshown in FIG. 6, so that every other apex may be engaged by a triggerwire. In other examples, the proximal stent 220 may have any number offirst proximal apices and second proximal apices. In one example, eachapex of the first proximal stent 220 may be configured as a firstproximal apex (i.e., each apex may include an end region 226 with anaperture 227).

FIG. 7 shows the proximal stent 220, with the proximal end of theproximal stent restrained in the partly compressed configuration by aconventional trigger wire system. FIG. 8 shows a partial longitudinalcross sectional view of one of the first proximal apices 221 a engagedby an axial trigger wire 142 as shown in FIG. 7. The axial trigger wire142 may exit the trigger wire guide 150 through the elongate aperture154 as described above. The axial trigger wire 142 may pass through theaperture 227 of the proximal stent 220 of the prosthesis 200 and thenreenter the trigger wire guide 150 through the elongate aperture 154. Inthis manner, the curve 144 of the axial trigger wire 142 may engage theend region 226 of the proximal stent 220 to restrain the end region inclose proximity to the trigger wire guide 150.

One advantage of the trigger wire system shown in FIGS. 7-8 is that theaxial trigger wires 142 may be disposed through the apertures 227 of thefirst proximal apices 221 a as opposed to being disposed through thebends 222 of the proximal stent 220. This may reduce the probabilitythat the axial trigger wires 142 and/or the struts 224 of the proximalstent 220 may become damaged upon compression of the prosthesis 200. Inother words, because the apertures 227 may not be pinched closed uponcompression of the prosthesis 200, pinching of the axial trigger wires142 may be avoided.

As shown in FIG. 7, each of the first proximal apices 221 a of theproximal stent 220 may be engaged by an axial trigger wire 142, whileeach of the second proximal apices 221 b may remain unengaged by theaxial trigger wires. Restraining the first proximal apices 221 a inclose proximity to the trigger wire guide 150 may indirectly restrainthe adjacent second proximal apices 221 b in a position that is closerto the trigger wire guide than in the expanded configuration. However,the second proximal apices 221 b may remain farther from the triggerwire guide 150 than the first proximal apices 221 a as shown in FIG. 7.

In one embodiment, the trigger wire system includes a circumferentialtrigger wire in addition to the axial trigger wires. The proximalportion of the circumferential trigger wire may extend at leastpartially circumferentially around the proximal stent of the prosthesisto restrain the proximal end of the prosthesis in the compressedconfiguration as further described below.

FIGS. 9-11 show an intermediate portion of one embodiment of thedeployment device 100 having a circumferential trigger wire 146. Thedeployment device 100 may include the guide wire catheter 110 and thetrigger wire guide 150 generally as described above with reference toFIGS. 1-5. FIG. 10 is a cross sectional view taken along line 10-10 ofFIG. 9. At least one axial trigger wire 142 may extend longitudinallywithin the annular space between the guide wire catheter 110 and thetrigger wire guide 150. For example, six axial trigger wires 142 mayextend longitudinally within the trigger wire guide 150 as shown inFIGS. 9-10. Additionally, or alternatively, the distal portion of thecircumferential trigger wire 146 may extend longitudinally within thetrigger wire guide 150.

In this embodiment, the trigger wire guide 150 may include at least onepair of openings in place of the at least one elongate aperture 154. Forexample, the trigger wire guide 150 may include six pairs of openings asshown in FIGS. 9-11. Each pair of openings may include a first opening154 a and a second opening 154 b. The first and second openings 154 a,154 b may be aligned with one another with respect to a circumference ofthe trigger wire guide 150. The second opening 154 b may be positionedlongitudinally proximal of the first opening 154 a. An axial triggerwire 142 may exit the trigger wire guide 150 through the first opening154 a, extend proximally external of the trigger wire guide, and reenterthe trigger wire guide through the second opening 154 b. In this manner,the curve 144 may be formed external of the trigger wire guide 150. Eachaxial trigger wire 142 may extend through a corresponding pair ofopenings. The pairs of openings may be aligned with one another withrespect to the longitudinal axis of the trigger wire guide 150 andspaced from one another circumferentially around the trigger wire guide.Although the deployment device 100 shown in FIGS. 9-11 may include sixaxial trigger wires extending through six pairs of openings, any numberof axial trigger wires (e.g., four axial trigger wires as describedabove with reference to FIGS. 3-5) extending through any number of pairsof openings may be used. Additionally, or alternatively, one or moreelongate apertures may be used in place of one or more of the pairs ofopenings as described above with reference to FIGS. 3-5.

The trigger wire guide 150 may include a pair of circumferential triggerwire openings. The pair of circumferential trigger wire openings mayinclude a first circumferential trigger wire opening 156 a and a secondcircumferential trigger wire opening 156 b. The first and secondcircumferential trigger wire openings 156 a, 156 b may be aligned withone another with respect to the circumference of the trigger wire guide150. The second circumferential trigger wire opening 156 b may bepositioned longitudinally proximal of the first circumferential triggerwire opening 156 a. The first circumferential trigger wire opening 156 amay be positioned longitudinally distal of the first openings 154 a, andthe second circumferential trigger wire opening 156 b may be positionedlongitudinally proximal of the second openings 154 b. Thecircumferential trigger wire 146 may exit the trigger wire guide 150through the first circumferential trigger wire opening 156 a, extendproximally and at least partially circumferentially around the triggerwire guide external of the trigger wire guide, and reenter the triggerwire guide through the second circumferential trigger wire opening 156 bas shown in FIG. 11 and further described below.

FIG. 11 shows a proximal portion of the prosthesis 200 loaded on thedeployment device 100. The prosthesis 200 may include a series of firstproximal apices 221 a and a series of second proximal apices 221 b asdescribed above with reference to FIGS. 6-7. Each pair of openings 154a, 154 b of the trigger wire guide 150 may be generally aligned with acorresponding aperture 227 of the proximal stent 220 of the prosthesis200. The first and second openings 154 a, 154 b may be spacedlongitudinally from one another such that each opening is accessiblethrough the aperture 227. For example, the first opening 154 a may begenerally aligned with a distal end of the aperture 227 while the secondopening 154 b may be generally aligned with a proximal end of theaperture 227. The axial trigger wire 142 may be disposed within theopenings 154 a, 154 b, as described above, such that the curve 144extends through the aperture 227. In this example, the curve 144 may bealigned with the aperture 227 as opposed to engaging the end region 226as described above. In other words, the end region 226 may not bedisposed between the curve 144 and the trigger wire guide 150 asdescribed above, but rather the curve 144 may be received within theaperture 227 of the proximal stent 220. The curve 144 of each axialtrigger wire 142 may be disposed within the corresponding aperture 227of the proximal stent 220 of the prosthesis 200 as shown in FIG. 11.Alternatively, the curve 144 may be disposed within any void near theproximal end of the proximal stent 220. For example, the curve 144 maybe disposed within the void between two adjacent struts of the proximalstent 220.

The first circumferential trigger wire opening 156 a may be generallyaligned with a void of the proximal stent 220 so that the firstcircumferential trigger wire opening may be accessible through theproximal stent. For example, the first circumferential trigger wireopening 156 a may be aligned with the void between two adjacent strutsof the proximal stent 220. The circumferential trigger wire 146 may exitthe first circumferential trigger wire opening 156 a and pass throughthe void in the proximal stent 220. The circumferential trigger wire 146may extend proximally and circumferentially to engage the proximal stent220. For example, the circumferential trigger wire 146 may extendthrough the curve 144 of at least one of the axial trigger wires 142.FIG. 12 shows a partial longitudinal cross sectional view of one of thefirst proximal apices 221 a engaged by a circumferential trigger wire146 as shown in FIG. 11. The circumferential trigger wire 146 may bereceived within the curve 144 and between the axial trigger wire 142 andthe proximal stent 220 as shown in FIGS. 11-12. The axial trigger wire142 may engage the circumferential trigger wire 146 to retain thecircumferential trigger wire in close proximity to the proximal stent220 and the trigger wire guide 150. In other words, the axial triggerwire 142 may prevent the circumferential trigger wire 146 from movingradially away from the trigger wire guide 150. The axial trigger wire142 also may retain the circumferential trigger wire 146 longitudinallybetween the distal end of the aperture 227 and the proximal end of theaperture. This may prevent the circumferential trigger wire 146 frommoving proximally, and potentially slipping off of the proximal end ofthe proximal stent 220, or moving distally, and potentially allowingexpansion of the proximal end of the proximal stent. In this manner, theproximal stent 220 may be restrained between the circumferential triggerwire 146 and the trigger wire guide 150 and in close proximity to thetrigger wire guide 150.

The circumferential trigger wire 146 may extend circumferentially aroundat least a portion of the proximal stent 220 and the trigger wire guide150 as shown in FIG. 11. The circumferential trigger wire 146 may bereceived within the curve 144 of each of the axial trigger wires 142around the circumference of the proximal stent 220. In this manner, thecircumferential trigger wire 146 may at least partially encircle anouter surface of the proximal stent 220 to restrain the proximal stentin close proximity to the trigger wire guide 150 (e.g., in thecompressed configuration). The circumferential trigger wire 146 mayextend proximally and reenter the trigger wire guide 150 through thesecond circumferential trigger wire opening 156 b. The proximal end ofthe circumferential trigger wire 146 may be received within the nosecone dilator 116 to maintain tension on the circumferential triggerwire.

A trigger wire system having a circumferential trigger wire may bebeneficial for multiple reasons. For example, the circumferentialtrigger wire 146 may extend circumferentially around the proximal stent220 to engage each of the proximal apices. In other words, thecircumferential trigger wire 146 may engage the first proximal apices221 a having the apertures 227 and the second proximal apices 221 bhaving the barbs 229. Thus, the circumferential trigger wire mayrestrain each proximal apex of the proximal stent 220 in close proximityto the trigger wire guide 150. In this manner, the circumferentialtrigger wire 146 may restrain the proximal end of the proximal stent 220in the compressed configuration.

Because the proximal stent 220 may be engaged by a singlecircumferential trigger wire 146 (which itself may be engaged by theaxial trigger wires 142), the proximal end of the prosthesis 200 may bereleased by retracting the single circumferential trigger wire asopposed to multiple axial trigger wires 142. This may reduce theretraction force required to release the proximal end of the prosthesis200. Such a reduced retraction force may provide a desirable tactilefeel for a physician during deployment of the prosthesis 200 to aid inprecise placement of the prosthesis within a body vessel. The ability torelease the proximal end of the prosthesis 200 by retracting a singletrigger wire may reduce the probability of the trigger wire becomingtangled (e.g., with other trigger wires) during deployment of theprosthesis.

The addition of the circumferential trigger wire 146 to the trigger wiresystem also may provide a safety factor to the deployment device 100.For example, it may become difficult or even impossible to retract thecircumferential trigger wire 146 from engagement with the axial triggerwires 142. This may be caused by the circumferential trigger wire 146snagging on a component of the prosthesis 200 or the delivery device 100or breakage of the circumferential trigger wire. In such a situation,the axial trigger wires 142 may be retracted to release thecircumferential trigger wire from engagement with the proximal stent220. In other words, the proximal stent 220 may be released byretracting either the circumferential trigger wire 146 or the axialtrigger wires 142. Providing alternative means of releasing the proximalstent 220 may enhance the safety of the deployment device 100.

The prosthesis 200 may be positioned within a body vessel of a patientusing conventional endovascular techniques. Once the prosthesis 200 isin the desired location within the body vessel, the sheath 130 may beretracted to enable partial expansion of the prosthesis 200 as shown inFIG. 2. The proximal end 202 of the prosthesis 200 may be restrained inthe compressed configuration by the circumferential trigger wire 146 asshown in FIG. 11. In this partially expanded configuration, theprosthesis 200 may be repositioned (e.g., rotated and/or translated)within the body vessel. Once the prosthesis 200 is positioned asdesired, the proximal end 202 of the prosthesis may be released toenable expansion of the prosthesis to the expanded configuration.

The proximal end 202 of the prosthesis may be released by manipulationof the trigger wire release mechanisms. For example, the circumferentialtrigger wire release mechanism 123 may be unlocked and retracteddistally relative to the guide wire catheter 110. Initial retraction ofthe circumferential trigger wire release mechanism 123 may pull theproximal end of the circumferential trigger wire 146 out of engagementwith the nose cone dilator 116. Further retraction of thecircumferential trigger wire release mechanism 123 may cause thecircumferential trigger wire 146 to slide out of engagement with each ofthe axial trigger wires 142. Upon disengagement of the circumferentialtrigger wire 146 from the axial trigger wires 142, the proximal stent220 of the prosthesis 200 may not be restrained by the circumferentialtrigger wire, and the proximal stent may expand to the expandedconfiguration. The circumferential trigger wire release mechanism 123may be further retracted to remove the circumferential trigger wire 146from the deployment device 100.

After removal of the circumferential trigger wire 146 from thedeployment device 100, the axial trigger wires 142 may remain loaded inthe deployment device 100 during retraction of the deployment devicefrom the body of the patient. Alternatively, the axial trigger wires maybe removed from the deployment device 100 prior to retraction of thedeployment device. For example, the axial trigger wire release mechanism121 may be unlocked and retracted distally relative to the guide wirecatheter 110. Initial retraction of the axial trigger wire releasemechanism 121 may pull the proximal ends of the axial trigger wires 142out of engagement with the nose cone dilator 116. The axial trigger wirerelease mechanism 121 may be further retracted to slide the axialtrigger wires 142 out of the openings 154 a, 154 b in the trigger wireguide 150 and to remove the axial trigger wires from the deploymentdevice 100. Removing the axial trigger wires 142 from the deploymentdevice 100 prior to retraction of the deployment device from the body ofthe patient may reduce the probability of catching or snagging any ofthe axial trigger wires on the prosthesis 200 during retraction of thedeployment device.

Although the trigger wire system has been described as engaging theproximal end of the prosthesis to restrain the proximal end in thecompressed configuration, the trigger wire system may engage the distalend or any other portion of the prosthesis in a similar manner torestrain the distal end or other portion of the prosthesis in thecompressed configuration. In one example, one trigger wire system mayengage the proximal stent of the prosthesis while another trigger wiresystem may engage a distal stent of the prosthesis. Alternatively, oradditionally, multiple trigger wire systems may engage any portion ofthe prosthesis (e.g., any stent of the prosthesis) to restrain thatportion in the compressed configuration.

While various embodiments of the invention have been described, theinvention is not to be restricted except in light of the attached claimsand their equivalents. Moreover, the advantages described herein are notnecessarily the only advantages of the invention and it is notnecessarily expected that every embodiment of the invention will achieveall of the advantages described.

I claim:
 1. An expandable endoluminal prosthesis and deployment device for deploying the expandable endoluminal prosthesis within a body vessel, the deployment device comprising: a proximal end and a distal end; an elongate member extending longitudinally along at least a portion of a length of the deployment device from the distal end to the proximal end and having an inner lumen; an expandable endoluminal prosthesis disposed about the elongate member, the expandable endoluminal prosthesis comprising a tube of graft material and at least one self-expanding stent, the self-expanding stent having an outer circumference; at least one axial trigger wire disposed in the lumen of the elongate member from the distal end of the deployment device, the at least one trigger wire extending outwardly from the lumen of the elongate member through an axial trigger wire aperture in the elongate member to form an axial loop external to the elongate member and through the stent; and a circumferential trigger wire extending out of a first circumferential trigger wire aperture in the enlongate member at an exit point on the elongate member, forming a single loop circumferentially around substantially the entire outer circumference of the stent to hold the stent in a compressed configuration and re-entering the elongate member at a position spaced from exit point, the single loop removably received under the axial loop of the at least one axial trigger wire such that the circumferential trigger wire is between the axial loop of the axial trigger wire and the stent without extending around the axial trigger wire.
 2. The deployment device of claim 1, wherein removal of the at least one axial trigger wire from over the circumferential trigger wire releases the stent from the compressed configuration.
 3. The deployment device of claim 1, wherein removal of the circumferential trigger wire from under the axial loop of the at least one axial trigger wire releases the stent from the compressed configuration.
 4. The deployment device of claim 1, wherein the at least one axial trigger wire comprises a plurality of axial trigger wires and the elongate member further comprises a plurality of pairs of axially spaced trigger wire apertures, wherein each of the plurality of axial trigger wires extends through a corresponding one of the plurality of pairs of axially spaced trigger wire apertures to form an axial loop over the circumferential trigger wire.
 5. The deployment device of claim 1, wherein the at least one axial trigger wire prevents the circumferential trigger wire from radial movement away from the external circumference of the stent.
 6. The deployment device of claim 1, wherein the at least one axial trigger wire prevents axial movement the circumferential trigger wire relative to the stent.
 7. The deployment device of claim 1, wherein the stent comprises proximal apices having an opening and the axial loop extends through a proximal apex opening and over the circumferential trigger wire.
 8. The deployment device of claim 1, wherein the at least one axial trigger wire comprises a plurality of axial trigger wires.
 9. The deployment device of claim 1, wherein the first circumferential trigger wire aperture is generally aligned with a void in the stent such that the first circumferential trigger wire exits the first circumferential trigger wire aperture and extends through the void in the stent to the outer circumference of the stent.
 10. The deployment device of claim 1, wherein the stent comprises proximal apices and proximal barbs, wherein the circumferential trigger wire restrains each proximal apex and each proximal barb in a compressed configuration.
 11. The deployment device of claim 1, wherein the self-expanding stent extends from an end of the expandable endoluminal device.
 12. An expandable endoluminal prosthesis and deployment device for deploying the expandable endoluminal prosthesis within a body vessel, the deployment device comprising: a proximal end and a distal end; an elongate member extending longitudinally along at least a portion of a length of the deployment device from the distal end to the proximal end and having an inner lumen; an expandable endoluminal prosthesis disposed about the elongate member, the expandable endoluminal prosthesis comprising a tube of graft material and at least one self-expanding stent having an external circumference; at least one axial trigger wire disposed in the lumen of the elongate member from the distal end of the deployment device, the at least one trigger wire extending outwardly from the lumen of the elongate member through an axial trigger wire aperture in the elongate member to form an axial loop external to the elongate member and through the stent; and a circumferential trigger wire extending out of a circumferential trigger wire aperture in the enlongate member at an exit point, forming a single loop circumferentially around substantially the entire outer circumference of the stent to hold the stent in a compressed configuration and re-entering the elongate member at a point on the elongate member spaced from the exit point, the single loop removably received under the axial loop of the at least one axial trigger wire such that the circumferential trigger wire is between the axial loop of the axial trigger wire and the stent without extending around the axial trigger wire; wherein both the circumferential trigger wire and the at least one axial trigger wire are manipulatable from the distal end of the deployment device such that the stent is released from the compressed configuration by either removing the circumferential trigger wire from between the axial loop of the at least one axial trigger wire or removing the at least one axial trigger wire from over the circumferential trigger wire.
 13. The deployment device of claim 12, wherein the axial trigger wire aperture is one aperture through which the at least one axial trigger wire exits the lumen to extend over the circumferential trigger wire and re-enters the lumen of the elongate member.
 14. The deployment device of claim 12, wherein the axial trigger wire aperture comprises a first aperture through which the at least one axial trigger wire exits from the lumen and a second aperture axially spaced from the first aperture into which the at least one axial trigger wire re-enters the lumen of the elongate member.
 15. The deployment device of claim 12, wherein the at least one axial trigger wire comprises a plurality of axial trigger wires and the elongate member further comprises a plurality of pairs of axially spaced trigger wire apertures, wherein each of the plurality of axial trigger wires extends through a corresponding one of the plurality of pairs of axially spaced trigger wire apertures to form an axial loop over the circumferential trigger wire.
 16. The deployment device of claim 12, wherein the first circumferential trigger wire aperture is generally aligned with a void in the stent such that the first circumferential trigger wire exits the first circumferential trigger wire aperture and extends through the void in the stent to the outer circumference of the stent.
 17. The deployment device of claim 12, wherein the at least one axial trigger wire prevents the circumferential trigger wire from radial movement away from the external circumference of the stent.
 18. The deployment device of claim 12, wherein the at least one axial trigger wire prevents axial movement the circumferential trigger wire relative to the stent.
 19. The deployment device of claim 12, wherein the stent comprises proximal apices and proximal barbs, wherein the circumferential trigger wire restrains each proximal apex and each proximal barb in a compressed configuration.
 20. The expandable endoluminal prosthesis and deployment device of claim 12, wherein the self-expanding stent extends from an end of the expandable endoluminal device. 